From mboxrd@z Thu Jan 1 00:00:00 1970 From: will.deacon@arm.com (Will Deacon) Date: Tue, 2 Feb 2010 16:22:25 +0000 Subject: [RFC PATCH 1/4] ARM: hw-breakpoint: add mechanism for hooking into prefetch aborts In-Reply-To: <1265127748-4587-1-git-send-email-will.deacon@arm.com> References: <1265127748-4587-1-git-send-email-will.deacon@arm.com> Message-ID: <1265127748-4587-2-git-send-email-will.deacon@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On ARM processors with hardware breakpoint and watchpoint support, triggering these events results in a debug exception. These manifest as prefetch and data aborts respectively. arch/arm/mm/fault.c already provides hook_fault_code for hooking into data aborts dependent on the DFSR. This patch adds a new function, hook_ifault_code for hooking into prefetch aborts in the same manner. Signed-off-by: Will Deacon --- arch/arm/include/asm/system.h | 3 +++ arch/arm/mm/fault.c | 11 +++++++++++ 2 files changed, 14 insertions(+), 0 deletions(-) diff --git a/arch/arm/include/asm/system.h b/arch/arm/include/asm/system.h index 058e7e9..7aa53e3 100644 --- a/arch/arm/include/asm/system.h +++ b/arch/arm/include/asm/system.h @@ -83,6 +83,9 @@ void arm_notify_die(const char *str, struct pt_regs *regs, struct siginfo *info, void hook_fault_code(int nr, int (*fn)(unsigned long, unsigned int, struct pt_regs *), int sig, const char *name); +void hook_ifault_code(int nr, int (*fn)(unsigned long, unsigned int, + struct pt_regs *), + int sig, const char *name); #define xchg(ptr,x) \ ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr)))) diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c index 9d40c34..9a04584 100644 --- a/arch/arm/mm/fault.c +++ b/arch/arm/mm/fault.c @@ -567,6 +567,17 @@ static struct fsr_info ifsr_info[] = { { do_bad, SIGBUS, 0, "unknown 31" }, }; +void __init +hook_ifault_code(int nr, int (*fn)(unsigned long, unsigned int, struct pt_regs *), + int sig, const char *name) +{ + if (nr >= 0 && nr < ARRAY_SIZE(ifsr_info)) { + ifsr_info[nr].fn = fn; + ifsr_info[nr].sig = sig; + ifsr_info[nr].name = name; + } +} + asmlinkage void __exception do_PrefetchAbort(unsigned long addr, unsigned int ifsr, struct pt_regs *regs) { -- 1.6.5.7